GSSP for Piacenzian Stage

Definition:

The base of the Piacenzian Stage is defined as the base of the beige
marl bed of the small-scale carbonate cycle 77. It corresponds to
precessional excursion 347 as numbered from the present, with an
astrochronological age estimate of 3.600 Ma. The GSSP is located in
the Punta Piccola section, Italy.

Location:

The Punta Piccola section is located on the southern coast of Sicily (Italy).
The section is represented on the Carta Topografica d'Italia in the 1:25,000
series, Foglio 271, Quadrante IV, NO (Porto Empedocle) at a latitude of
37Â°17'20" N and a longitude of 13Â°29'36" E of Greenwich. The section is located
along the road from Porto Empedocle to Realmonte, 4km to the east of Capo
Rossello and about 3km to the W-NW of Porto Empedocle.

Sedimentology:

The Punta Piccola section is the upper part of the Rossello Composite
Section, which is made up by about 100m of alternating marls and
limestones of the Trubi Formation, transitionally grading upward into
the more marly Monte Narbonne Formation. The Monte Narbonne Formation
is characterized by the cyclical occurrence of laminated (sapropelic)
layers. The transition from the Trubi Formation to the Monte Narbonne
Formation occurs in the Punta Piccola section at about 20m from its
base. The depositional environment for the boundary is inferred to be
a slope-basin setting with water depth ranging from 800 to 1000m.

Primary Markers:

Astrocyclostratigraphy:
The base of the Piacenzian Stage is defined as the base of the beige
marl bed of the small-scale carbonate cycle 77. It corresponds to
precessional excursion 347 as numbered from the present, with an
astrochronological age estimate of 3.600Ma.Paleomagnetics:
The section spans the interval from the upper part of the Gilbert
Chron (C2Ar) through the entire Gauss Chron and to the lowermost part
of the Matuyama Chron. The Gilbert-Gauss magnetic reversal is recorded
immediately above the GSSP within the same precessional cycle, having
an astrochronological age of 3.596Ma.

Secondary Markers:

Foraminifera:
In the Mediterranean the base of the Piacenzian can be recognized by
the first influx of Globorotalia crassaformis (3.60 Ma) and by
the temporary disappearance of Globorotalia puncticulata (3.57
Ma). In low and mid-latitude areas outside of the Mediterranean the
last occurrence of Globorotalia margeritae (3.58 Ma) and
Pulleniatina primalis (3.65) are close to the boundary.